Layer 2 blockchain · settles to BNB Smart Chain
opBNB ticker BNB
Summary
Optimistic rollup on BNB Smart Chain. One sequencer orders transactions into L2 blocks, one every 250 ms since the Fourier hard fork of 7 January 2026. A batcher posts compressed transaction batches to BNB Smart Chain as blob transactions, the data path since the Haber upgrade of June 2024, and any node can rebuild the L2 chain from them. A proposer posts L2 output roots to the L2OutputOracle contract on BNB Smart Chain; withdrawals are proven against a posted root and paid out after a 7-day challenge window. BNB Chain's docs describe fraud proofs that anyone can submit, but the contract in BNB Chain's opbnb repository lets only one proposer address post outputs and only one challenger address delete them. Nodes run op-node and op-geth, BNB Chain's forks of the OP Stack clients. Block production uses no stake or work of its own. 156815172223
Design
- System
- Layer 2 blockchainopBNB Mainnet (chain ID 204) is an optimistic rollup that BNB Chain built on the Bedrock version of the OP Stack; it posts its transaction data to BNB Smart Chain and settles there. BNB, bridged in from BNB Smart Chain, is the gas asset, and opBNB has no token of its own. BNB Chain's FAQ describes opBNB as a rollup on BNB Smart Chain that is not part of the Superchain.
- Settles to
- BNB Smart ChainBatches are posted to BNB Smart Chain as blob transactions and output roots to its L2OutputOracle contract. Deposits enter through the portal contract on BNB Smart Chain; withdrawals need a proof step and can be claimed after a 7-day challenge window. Since node release v0.5.5 the sequencer and derivation read only finalized BNB Smart Chain blocks, so opBNB's finalized head depends on that chain's fast finality. Ordinary BSC nodes keep blob data about 18 days, per BNB Chain's Haber announcement and BNB Smart Chain's current node code.
- Settlement family
- Ethereum / EVM
- Scarce resource
- Other
- State model
- Accounts
- Finality
- Other
- Who makes blocks
- One sequencer, which BNB Chain's protocol FAQ says the opBNB team operates and calls a centralized component; the same FAQ says individual users cannot run validator or aggregator nodes. BNB Chain's docs list one batch sender address and one output proposer address on BNB Smart Chain. Who holds the challenger role was not sourced.
- Fork choice
- No open L2 fork choice. The canonical chain is the one derived from batch data on BNB Smart Chain; a block the sequencer has produced but not yet committed there rests on the sequencer alone. BNB Chain's FAQ says an L2 block is finalized once its batch sits in a finalized BNB Smart Chain block, and since node release v0.5.5 (released November 2025) the sequencer and derivation follow BNB Smart Chain's finalized block, which its fast finality normally gives within two blocks.
Qualifications
- Scarce resource · Not applicable. Recorded as other. opBNB's own terms: blocks come from a single sequencer run by the opBNB team, with no stake or work of its own; security rests on batch data posted to BNB Smart Chain, on output roots that a challenger can remove during a 7-day window, and on BNB Smart Chain's own validators.
- Finality · Partial. Recorded as other. opBNB's own terms: the latest (unsafe) block is one the sequencer has produced, and a finalized block is one whose batch sits in a BNB Smart Chain block that BNB Smart Chain has finalized; BNB Chain's FAQ, last revised in 2024, says a gap of more than 200 blocks between them is expected. Withdrawals to BNB Smart Chain wait a further 7-day challenge window.
- Proof system · Contested. BNB Chain's docs say anyone can challenge an invalid output with a fraud proof during the 7-day window and that a dishonest sequencer's bond may be slashed. The L2OutputOracle contract in BNB Chain's opbnb repository lets only one proposer address post outputs and only one challenger address delete them, and the protocol address list shows that contract and no dispute-game contracts. A 2024 zero-knowledge fault-proof design was published as a proof of concept.
- Data availability · Applies. Batches go to BNB Smart Chain as blob transactions since the Haber upgrade (June 2024). Ordinary BSC nodes keep blob data about 18 days, so rebuilding older history needs an L1 endpoint that keeps blobs longer or a snapshot. BNB Chain's docs also name BNB Greenfield as a possible data layer; no Greenfield data path for opBNB batches was verified.
- Withdrawal window · Applies. Withdrawals through the official opBNB bridge wait 7 days after the user submits the withdrawal proof; BNB Chain's docs point users who want faster exits to third-party bridges, which carry their own trust models.
- Upgrade authority · Unknown. BNB Chain's docs list a ProxyAdmin contract and a SystemConfig contract on BNB Smart Chain for opBNB, and the oracle code says the proposer and challenger can be changed by upgrade. Who controls these contracts, and whether upgrades have a delay, was not sourced.
Tradeoffs
- Emphasizes
- Scalability
- Gives up
- Decentralized operation and trust-minimized exits: one team-run sequencer orders every transaction, one authorized proposer posts the output roots that withdrawals rely on, and in the reviewed contract code only one challenger address can remove a wrong root during the 7-day window. Who can upgrade the opBNB contracts on BNB Smart Chain, and with what delay, was not sourced.Security is not listed as an emphasis. opBNB's data availability rests on BNB Smart Chain, including that chain's validator set and its limited blob retention, and its output checks rest on permissioned roles, while BNB Chain's docs describe open fraud proofs. Readers who give the BNB Smart Chain anchor more weight may reasonably disagree.
- Full node at home
- Demanding 91011152539BNB Chain's node cheat sheet (May 2025) gives op-geth a minimum of 12 CPU cores and 10 GB RAM (16 cores and 32 GB recommended), storage with at least 3,000 IOPS and 1 TB or more, and a 125 MB/s link; its local-node guide (revised October 2025) asks for 16 GB RAM and 500 GB free. Archive state passed 5.6 TB in May 2024, with no archive snapshot. A node also needs a BNB Smart Chain RPC; BSC nodes keep blob data about 18 days (still so in BSC's current code), so syncing older history needs an endpoint that keeps blobs longer or a NodeReal snapshot.
- Throughput claims
- Theoretical peak: 4,761 tx/s 617192426Theoretical peak; not comparable across chains or with observed load.BNB Chain's arithmetic: a 100-million-gas block holds about 4,761 plain transfers of 21,000 gas each, stated per second when blocks were 1 second apart.Undated design arithmetic on BNB Chain's opBNB product page and protocol FAQGas-limit arithmetic that assumes only simple transfers; it is not a measurement of observed load. It was stated for 1-second blocks. The interval has since fallen to 500 ms (April 2025) and 250 ms (January 2026), while a read on 2026-09-29 still showed a 100-million-gas block limit, and BNB Chain has not published a revised figure. It ignores the cost and capacity of posting batch data to BNB Smart Chain, state growth and node hardware limits. BNB Chain's own pages give other figures for the same claim, so it is kept only as a design claim.
Scaling layers
No scaling layer recorded in this profile.
Capabilities
| Capability | How it is provided | Notes and sources |
|---|---|---|
| Account abstraction | Structured assessment pending | Not yet assessed for any chain. |
| Atomic swaps | Unknown | No trust-minimized swap mechanism on opBNB was reviewed. EVM contracts could host hash- and time-locked swaps, but none was verified. |
| Authenticated data publication | Unknown | Not yet assessed under this row's current definition. BNB Chain's docs point opBNB developers to BNB Greenfield, a separate chain, for storage; that path was not assessed against this row. 12 |
| Light clients | Unknown | No opBNB light client was reviewed. Output roots posted to BNB Smart Chain, and full nodes that serve account proofs at the latest posted root, are building blocks for proof-based checks, but the roots come from one authorized proposer and are not proven when posted. 922 |
| Native staking or delegation | Structured assessment pending | Not yet assessed for any chain. |
| On-chain governance | Structured assessment pending | Not yet assessed for any chain. |
| Parallel execution | Structured assessment pending | Not yet assessed for any chain. |
| Payment or state channels | Unknown | No payment or state channel layer anchored to opBNB was reviewed. |
| Programmable spending | Native (protocol or core-team software) Earlier definition | opBNB runs EVM smart contracts on op-geth, BNB Chain's fork of the OP Stack execution client, so spend conditions are written as contracts. The Haber upgrade added a precompile for secp256r1 signature checks (EIP-7212), and the Wright upgrade added transaction bundles and zero-gas-price transactions for sponsored use. 7131516 |
| Protocol-verified messaging | Structured assessment pending | Not yet assessed for any chain. |
| Reversible transfers or recovery | Unknown | Not yet assessed under this row's current definition. BNB Chain runs a Safe-based multi-signature wallet service on opBNB; an owner threshold alone meets neither part of this row, and no delay or recovery module on opBNB was reviewed. 14 |
| Rollups | Unknown | Rollups or other chains anchored to opBNB were not reviewed. opBNB itself is a rollup on BNB Smart Chain, described in the mechanism and settlement notes of this profile. |
| Shielded transfers | Structured assessment pending | Not yet assessed for any chain. |
| Signed partial offers | Unknown | Not yet assessed under this row's current definition. |
Reading these values
- How this feature is provided
- Built into the protocol, core-team software or independent software says where a feature lives and who can change it. These are implementation layers, not quality: core-team software is not closer to the protocol than independent software.
- Structured assessment pending
- The shared review has not assessed this feature for any chain yet (Account abstraction, Native staking or delegation, On-chain governance, Parallel execution, Protocol-verified messaging and Shielded transfers). That does not mean it is absent, and a chain’s profile may already describe it.
- Unknown
- The review has not established this for this chain under the current definition; the note beside it says why. Unknown is not absent and not a low score. A feature reads “Not present” only when a source shows it is absent.
- Earlier definition
- Payment or state channels, Programmable spending and Rollups keep the earlier definition until the next fact-check. There, “Native” does not separate the protocol from core-team software, “Ecosystem software” does not say who publishes it, and “Partial” does not say which layer.
- Reading across rows
- The list of capabilities is incomplete. Do not read these rows as a chain leading or lagging overall.
Ecosystem & custody
| Product type | Status | Notes and sources |
|---|---|---|
| Automated market makers | ThinPancakeSwap (v2 and v3 pools), LuigiSwap, THENA V1 | PancakeSwap's contract list gives opBNB addresses for its v3 contracts, and its docs name opBNB among the chains it runs on. DeFiLlama also indexes several smaller opBNB exchanges, including LuigiSwap, Binary Swap, LeetSwap, CUBISwap and THENA V1. The amounts DeFiLlama showed locked in these exchanges on opBNB were small at review, hence thin; operators, audits and liquidity depth were not reviewed. 303132 |
| Issuer-native stablecoins | Unknown | Circle's USDC contract list and Tether's supported-protocol list do not include opBNB, and World Liberty Financial's USD1 address list has no opBNB entry. BNB Chain's docs say Binance opened opBNB deposits and withdrawals in November 2023 with BNB, FDUSD and USDT in its initial list, but who issued those opBNB token contracts, and whether First Digital issues FDUSD there directly, was not confirmed; First Digital's page blocked this review. 12333435 |
| Algorithmic stablecoins | Unknown | Algorithmic or hybrid stablecoins on opBNB were not reviewed. |
| Bridges | Native to the protocolopBNB Bridge (standard bridge and portal contracts on BNB Smart Chain), zkBridge (Polyhedra), named in opBNB's docs, rhino.fi, named in opBNB's docs | BNB, BEP-20 tokens and messages move between BNB Smart Chain and opBNB through the rollup's own contracts; BNB Chain runs the opBNB Bridge app for them and lists it on its bridge page. Withdrawals are proven and then claimed after 7 days. BNB Chain's docs also name zkBridge and rhino.fi for faster transfers, and DeFiLlama lists Symbiosis, Meson and Wan Bridge on opBNB; those were not reviewed. Risk: Official-bridge withdrawals depend on output roots that one authorized proposer posts and that only one challenger address can remove, per the contract code in BNB Chain's repository, not on open fraud proofs; who can upgrade the bridge contracts was not sourced. Third-party bridges carry their own signer or verifier trust, which was not assessed, and a wrapped asset is only as sound as the bridge that minted it. 4581322282932 |
| Block explorers | Established in the ecosystemopBNBScan (NodeReal), opBNB BscScan | BNB Chain's network page lists opBNBScan and opBNB BscScan for mainnet, and its developer pages attribute opBNBScan to NodeReal; opBNBScan served its explorer on 2026-09-29. BscScan's opBNB site refused scripted access in this review, but Etherscan's API chain list, read on 2026-09-29, names opbnb.bscscan.com as the opBNB Mainnet explorer and shows it as online. Explorer indexes are provider data, not canonical consensus. 2122740 |
| Hardware wallets | Unknown | See custody rows: Trezor says its BNB support covers BNB Smart Chain only, on a page that lists opBNB as a separate BNB chain, and no Ledger path for opBNB was confirmed. opBNB's docs describe wallet setup with MetaMask and Trust Wallet and do not cover hardware wallets. 3363738 |
Hardware-wallet custody
| Device maker | Status | What users can and cannot do |
|---|---|---|
| Ledger | UnknownSame as native: Unknown | Ledger's published Ledger Wallet currency list (@ledgerhq/cryptoassets 13.56.0) has no opBNB entry and no network with chain ID 204, and Ledger's BNB Chain support article served only a script-rendered shell to this review, so neither support in Ledger Wallet nor a documented third-party signing path was confirmed. opBNB's own wallet guide covers MetaMask and Trust Wallet without mentioning hardware wallets. 336 |
| Trezor | None foundSame as native: No | Cannot: Use opBNB in Trezor Suite: Trezor's BNB page lists opBNB among the BNB chains and says Trezor only supports BNB Smart Chain transactionsTrezor's statement is general rather than an opBNB page: its BNB page names opBNB as one of the BNB chains before saying Trezor only supports BNB Smart Chain transactions, and its Trezor Suite guide says support is specific to BNB Smart Chain only. Signing opBNB transactions with a Trezor through a general EVM wallet set to chain ID 204 was not documented by Trezor or opBNB and was not tested. 3738 |
Public data
iKnow Blockchain has no public-data lookups for opBNB yet. This is a limit of the service, not a statement about the network.
| Lookup | Status | What it covers and its limits |
|---|---|---|
| Address or account | Not available yet | Public-data lookups for this chain are not built yet. |
| Tokens and assets | Not available yet | Public-data lookups for this chain are not built yet. |
| NFTs | Not available yet | Public-data lookups for this chain are not built yet. |
| Transactions | Not available yet | Public-data lookups for this chain are not built yet. |
Sourced developments
Developments: Reviewed Sep 29, 2026 Next review due Oct 9, 2026, 12:00 UTC.
Publication date · newest first
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opBNB node v0.5.6 and op-geth v0.5.11 fix sync and recovery problems without a hard fork
BNB Chain released opBNB node v0.5.6, which fixes a peer-to-peer sync stall that could leave a restarted node's latest block stuck for minutes, and op-geth v0.5.11, which makes path-based state recovery after an unclean shutdown reliable and keeps withdrawal proofs collected during recovery. Both update the Go toolchain and security-related dependencies.
- Implementation:shipped in opbnb v0.5.6 and op-geth v0.5.11
- Release:optional upgrade
- Activation:no activation; takes effect when each node upgrades
Sources: BNB Chain (GitHub) — opBNB v0.5.6 release notes (external site) · BNB Chain (GitHub) — op-geth v0.5.11 release notes (external site)
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Laplace hard fork proposed for 100 ms opBNB blocks; alpha builds only
BNB Chain opened pull requests in its op-node and op-geth repositories for a hard fork named Laplace, which would cut opBNB's block interval to 100 ms, and tagged v0.6.0.alpha builds of both. The pull requests were still open at review and no testnet or mainnet date had been published.
- Proposal:open pull requests in bnb-chain/opbnb and bnb-chain/op-geth
- Implementation:alpha builds tagged v0.6.0.alpha
- Release:no stable release
- Activation:no testnet or mainnet date published
Sources: BNB Chain (GitHub, bnb-chain/opbnb) — feat: implement Laplace hardfork in op-node (pull request #337) (external site) · BNB Chain (GitHub, bnb-chain/op-geth) — feat: op-geth supports Laplace hardfork (pull request #320) (external site) · BNB Chain (GitHub) — bnb-chain/opbnb releases Atom feed (external site) · BNB Chain (GitHub) — bnb-chain/op-geth releases Atom feed (external site)
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op-geth v0.5.10 limits single transactions to 16,777,216 gas in its pool and block building
BNB Chain released op-geth v0.5.10, which enforces a per-transaction gas limit of 16,777,216 (EIP-7825) both when a transaction enters the pool and when blocks are packed, to stop oversized transactions from affecting the network. The release also adds bundle-pool logging and sets the bundle lifetime to 240 blocks to match the current 250 ms block time.
- Implementation:shipped in op-geth v0.5.10
- Release:released; no deadline stated
- Activation:applies on nodes running v0.5.10 or later; sequencer adoption date not confirmed
Sources: BNB Chain (GitHub) — op-geth v0.5.10 release notes (external site) · BNB Chain (GitHub) — bnb-chain/op-geth releases Atom feed (external site)
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Fourier hard fork set for 7 January 2026 to cut opBNB's block interval to 250 ms
BNB Chain released opBNB node v0.5.5 and op-geth v0.5.9, which set the Fourier hard fork's mainnet time to 03:00 UTC on 7 January 2026; the fork halves the block interval from 500 ms to 250 ms. The fork was first released in v0.5.4 in October 2025 with testnet activation set for 6 November 2025. v0.5.5 also made the sequencer and derivation follow BNB Smart Chain's finalized block.
- Implementation:shipped in opbnb v0.5.4 and v0.5.5 and op-geth v0.5.8 and v0.5.9
- Release:mandatory node upgrade before the fork time
- Activation:mainnet 2026-01-07 03:00 UTC per BNB Chain's announcement, which marks the upgrade passed
Sources: BNB Chain (GitHub) — opBNB v0.5.5 release notes (Fourier mainnet time) (external site) · BNB Chain (GitHub) — opBNB v0.5.4 release notes (Fourier hard fork implementation) (external site) · BNB Chain Docs (Announcements) — Fourier Upgrade of opBNB (external site) · BNB Chain (GitHub) — op-geth v0.5.10 release notes (external site) · BNB Chain (GitHub, bnb-chain/opbnb) — feat: replace l1 head with l1 finalized block as sequencer and derivation head (pull request #319) (external site)
Topics your AI can explain
Your AI can explain these topics for opBNB through the connection, with sources.
Known gaps
What this profile's review did not establish:
- The proposer and challenger addresses and the finalization period set in the deployed L2OutputOracle on BNB Smart Chain were not read on chain; the single-proposer and single-challenger rules come from the contract source on the main branch of BNB Chain's opbnb repository and the documented 7-day window.
- Who controls the ProxyAdmin and SystemConfig contracts, and whether contract upgrades have any delay, was not sourced.
- BNB Chain's docs describe open fraud proofs and a sequencer bond that can be slashed; no deployed dispute-game or bond contract for opBNB mainnet was found, and the 2024 zero-knowledge fault-proof work was a proof of concept.
- The sequencer's legal operator is named only as the opBNB team, on an FAQ page last revised in July 2024.
- How long the sequencer can delay a deposit or forced transaction sent through the portal on BNB Smart Chain was not verified after BNB Smart Chain's faster blocks; a March 2025 node hotfix changed the sequencing window setting.
- Where opBNB fees go and whether any part is burned was not sourced. BNB Chain's gas page lists an 8 wei floor base price, while the Wright upgrade set the base fee to 0 and a 2026-09-29 read showed a base fee of 0.
- Blob retention was read from BNB Smart Chain's current node source code (about 18.2 days, with the block count set from its 0.45-second interval), not measured on live nodes; whether BNB Greenfield holds opBNB batch data was not verified.
- Node hardware guidance conflicts across BNB Chain pages (at least 16 GB RAM and 500 GB in the local-node guide revised October 2025; 12 to 16 cores and 1 TB or more in the May 2025 cheat sheet), and current chain size was not measured.
- Ledger support for opBNB was not confirmed either way; Ledger's support article could not be read without a browser.
- Trezor use through a general EVM wallet on chain ID 204 was not documented or tested.
- Who issues the FDUSD and USDT contracts used on opBNB was not confirmed from the issuers.
- Third-party bridges (zkBridge, rhino.fi, Symbiosis, Meson, Wan Bridge) were not reviewed for trust model or current opBNB support.
- The Laplace hard fork (100 ms blocks) exists only as an alpha pre-release and open pull requests from April 2026; no activation date was published.
- Some BNB Chain pages are stale: the repository README and gas FAQ still give 1-second blocks, and the metrics page lists figures from 2024. This profile relies on dated hard-fork announcements and releases instead.
- Trust-minimized swaps, reversible transfers or recovery, light clients, channels, algorithmic stablecoins and chains anchored to opBNB were not reviewed.
- BNB Chain's throughput figure for opBNB has not been restated since the block interval fell to 250 ms.
Sources
Oldest dated source check: Source checked Sep 29, 2026 Next check due Oct 29, 2026.
- opBNB Overview (external site)
- Network Information - opBNB (external site)
- Wallet configuration - opBNB (external site)
- Deposit BNB(tBNB) to opBNB (external site)
- Withdraw from opBNB (external site)
- Protocol FAQs - opBNB (external site)
- Cross Chain FAQs - opBNB (external site)
- opBNB Protocol addresses (external site)
- Best Practices for opBNB Node Configuration (external site)
- Running a Local Testnet or Mainnet Node (external site)
- Developers Cheat Sheet (hardware requirements) - opBNB (external site)
- Developer Tools - opBNB (external site)
- Quick Guide - opBNB (external site)
- BNB Chain Safe Multi-Sig Wallet Service (external site)
- Haber Upgrade of opBNB (external site)
- Wright Upgrade of opBNB (external site)
- Fourier Upgrade of opBNB (external site)
- Gas and Fees - opBNB (external site)
- Volta Upgrade of opBNB (external site)
- bnb-chain/opbnb releases (external site)
- Zk fault proof for opBNB (external site)
- L2OutputOracle.sol (main branch): single proposer and single challenger roles (external site)
- feat: replace l1 head with l1 finalized block as sequencer and derivation head (pull request #319) (external site)
- opBNB: A high-performance optimistic layer-2 solution for BNB Smart Chain (external site)
- opbnb-snapshot README (external site)
- opBNB mainnet public RPC (eth_getBlockByNumber read 2026-09-29) (external site)
- opBNBScan - opBNB Blockchain Explorer (external site)
- opBNB Bridge - Transfer Tokens between BSC & opBNB (external site)
- BNB Chain Bridge (external site)
- PancakeSwap v3 contract addresses (external site)
- PancakeSwap documentation (external site)
- DeFiLlama protocols API (entries listing opBNB) (external site)
- USDC contract addresses (external site)
- Supported Protocols (external site)
- Contract Addresses - USD1 (external site)
- @ledgerhq/cryptoassets 13.56.0 currency list (external site)
- What is BNB token and BNB Smart Chain? (external site)
- Managing BNB Smart Chain (BSC) & BEP-20 Tokens in Trezor Suite (external site)
- bsc params/protocol_params.go (master): blob retention constants (external site)
- Etherscan API V2 supported chain list (opBNB Mainnet, chain ID 204) (external site)
Report an error
Found something wrong or out of date? Reporting is free, and every chain goes through the same process. Published corrections appear in the public log.
Funding disclosure
Funding disclosures appear here when an upkeep arrangement exists, in the form “Upkeep funded by [name]; verdicts unaffected.” The funder ledger has not been published yet. Neutrality & funding